AB1426 CHRONIC RECURRENT MULTIFOCAL OSTEOMYELITIS AND BOWEL INFLAMMATION: A MONOCENTRIC COHORT
Authors: S. Costi, S. Germinario, M. R. Pellico, A. Amati, M. Gattinara, C. Chighizola, A. Marino, R. Caporali
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory disease of bone primarily affecting children and adolescents. Although CRMO can be associated with inflammatory bowel disease (IBD)<sup>[1]</sup>, the prevalence of subclinical bowel inflammation and its relationship with other autoimmune bowel disorders remains uncertain. <h3>Objectives</h3> This study aims to evaluate the prevalence of subclinical bowel inflammation in CRMO patients and the potential association with celiac disease. <h3>Methods</h3> Clinical records of patients diagnosed with CRMO attending the Unit of Pediatric Rheumatology of Gaetano Pini Hospital were retrospectively reviewed. Fecal calprotectin and screening for celiac disease were performed in all patients within 2 years after diagnosis. <h3>Results</h3> Complete data from 24 patients were collected (83% female). The mean age at diagnosis was 10.1 (DS ± 2.7) and the median follow-up time was 68.5 months (IQR 97.5). The first symptom at onset was bone pain (100%), while only 4 patients (17%) complained of gastrointestinal symptoms (abdominal pain, weight loss, diarrhea). The patients in our cohort had no specific comorbidity, except for two patients suffering from hemophilia and pyoderma gangrenosum, respectively. 96% (23/24) of patients had polyostotic disease. During the follow-up period, 9 patients (38 %) received only non-steroidal anti-inflammatory drugs therapy, 10 patients (42%) received conventional disease-modifying antirheumatic drugs (methotrexate), 4 (17%) received anti-tumor necrosis factor (TNF) agents and 12 (50%) received intravenous bisphosphonates. Cumulative treatments are summarized in Figure 1. Two patients, both in clinical remission off medication, were lost to follow-up. Calprotectin levels were normal in 100% of patients, while 3 patients (13%) presented positive screening test for celiac disease with a positive test for IgA anti-tissue transglutaminase antibodies (Table 1). In one of these patients, the diagnosis of celiac disease was confirmed by duodenal biopsy. After a gluten-free diet, the patient, who was off medication, achieved complete clinical remission and a remarkable improvement in radiological lesions. <h3>Conclusion</h3> The link between autoinflammatory bone disease and intestinal inflammation should be further investigated since it might open insight into bone inflammation and new therapeutic options. In our experience, controlling bowel disease may promote a better response to CRMO treatments. On the other hand, the percentage of unexplained bone pain in celiac disease is high, and, in this scenario, a possible inflammatory bone disorder should be ruled out. <h3>Reference</h3> [1] Audu GK, Nikaki K, Crespi D, Spray C, Epstein J. Chronic recurrent multifocal osteomyelitis and inflammatory bowel disease. J Pediatr Gastroenterol Nutr. 2015 May;60(5):586-91. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Stefania Costi: None declared, Sabino Germinario: None declared, Maria Rosa Pellico: None declared, Andrea Amati: None declared, Maurizio Gattinara: None declared, Cecilia Chighizola: None declared, Achille Marino: None declared, Roberto Caporali Speakers bureau: AbbVie, Amgen, BMS, Celltrion, Fresenius, Galapagos, Janssen, Lilly, Novartis, Pfizer, UCB, Consultant of: AbbVie, Fresenius, Galapagos, Lilly, Novartis, Pfizer, UCB.